(a) Field of the Invention
The present invention relates to an apparatus for coloring, decoloring and drying sample carriers in electrophorestic systems.
(b) Description of the Prior Art
The electrophoresis is utilized for measuring proteins contained in blood serum in clinical inspection laboratories, etc. of hospitals and medical institutes. For the electrophoresis, blood serum to be analyzed is applied onto a carrier which is made of cellurose acetate or the similar material and then the carrier is electrically energized for developing fractionated patterns of the blood serum. The carrier is colored with a coloring liquid agent and, after the area other than the blood serum is decolored, the sample is subjected to colorimetry for quantitative determination. Conventionally, various processes of the electrophoresis were manually carried out with low efficiency. Further, analysis by the electrophoresis required highly delicate skill and the conventional electrophoretic system had a defect that it offered analytical results which are different depending on individual analysts' measuring skills.
In view of such circumstances, there have hitherto been developed automatic electrophoretic systems which can automatically carry out the processes of the electrophoresis for the purpose of enhancing measuring efficiency and eliminating analytical variations due to difference in measuring skills depending on indivisual analysts. As an apparatus for carrying out the coloring, decoloring and drying processes out of the various steps performed by the automatic electrophoretic systems, there has known an apparatus disclosed by Japanese published unexamined patent application No. 158694/54 (U.S. Pat. No. 4,222,843). This coloring-decoloring-drying apparatus is designed in such a manner that a carrier is bonded onto circumference of a drum, rotated therewith so as to pass through a liquid trough filled with a coloring liquid agent for coloring said carrier and then through a trough filled with a decoloring liquid agent for decoloring said carrier, and then is dried by exposing it to hot air blast or the similar means. An outline of this coloring-decoloring-drying apparatus will be described with reference to FIG. 1. A carrier 1 on which fractionated patterns of a sample have been developed in an electrophoretic apparatus (not shown) is fed between a roller 2 and a drum 3 by an adequate means. The carrier is soaked with a buffer solution and is therefore bonded onto the drum 3 consecutively from the leading end of said carrier. When the leading end of the carrier has passed just beyond another roller 4, rotation of the drum is stopped so that the carrier 1 is kept in the condition where it is bonded onto the outer circumference of the drum 3 while being held with both the rollers 2 and 4. With the carrier 1 kept in this condition, the drum 3 is rotated together with the rollers 2 and 4 so as to rotate the carrier 1 while it is bonded onto the drum 3 and held with the rollers 2 and 4. A liquid trough 5 is filled with a coloring liquid agent, and therefore the carrier is colored since it passes through the liquid agent repeatedly during its rotation. The carrier is decolored in the similar way when the trough is filled with a decoloring liquid agent in place of the coloring liquid agent. After the carrier has been colored and decolored as described above, it is dried with hot air blast supplied from a blower port (now shown), and then the drum 3 only is rotated to feed the carrier 1 to the next process.
The coloring-decoloring-drying apparatus described above has a surface 3a having a curvature lower than the imaginary circular circumference of the drum 3 and serving to prevent the carrier 1 from being torn due to contraction at the drying process. Since degree of the contraction is different depending on material of the carrier, curvature of the surface 3a should ideally be varied depending on contraction degree of the carrier. Further, when the carrier has a short length, it is required to use a drum having a small diameter. In such a case, the carrier bonded onto the drum is held in a strongly curved condition and such a curved form remains at the subsequent processes, thereby causing inconvenience at the processes after the coloring and decoloring. Moreover, the drum type of apparatus shown in FIG. 1 has a drawback that it has a very complicated mechanism and requires a large number of component parts.